This star chart shows the track of asteroid 2004 FH at the time of closest
approach as it sped by Earth on the night of March 18-19. Sadly, the object
was not well placed for U.K. observers, skimming the southwest horizon when
at its brightest.

Image credit: Astronomy Now

Discovered by astronomers of MIT's Near-Earth Asteroid Research (LINEAR) survey
just two days previously, this house-sized body made the closest flyby of Earth
ever predicted at 10 p.m. (GMT) on March 18th. It missed us by just 26,500 miles
— one ninth the distance of the Moon.

Since it is so small and passed so close, the apparent brightness of 2004 FH
varied tremendously during its few hours of fame, reaching a peak of about visual
magnitude +10 by 9 p.m. GMT.

Its apparent path against the stars for an observer situated close to the centre
of the British Isles is shown at hourly intervals around the point of closest
approach, when it traversed the apparent width of the Full Moon every
minute. For an observer watching through a telescope, the motion would be immediately
obvious.

Unfortunately for U.K. observers, the viewing prospects were not good. The asteroid
skimmed the southwest horizon when at its brightest, and by dusk on March 19th it will
have faded to magnitude +20 as it recedes from Earth in the direction of northern Cetus.

Given the orbit now determined for 2004 FH, it appears to belong to the Aten class
of asteroids. It takes nearly nine months to orbit the Sun in a plane close to that
of the Earth. The asteroid is currently near aphelion (furthest from the Sun in its
orbit), but its noticeably eccentric path can take it inside the orbit of Venus.

The PlanetsFrom tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets. GET YOUR COPY

Hubble RebornHubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts. GET YOUR COPY

3D UniverseWitness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D! GET YOUR COPY